ANIMAL PARASITES 107 



soil have been devised. The most used employs the Baermann 

 apparatus as modified by Cort and his associates in hookworm 

 work. 



This isolation apparatus consists of a glass funnel, the outlet 

 of which is closed by a clamp on a piece of rubber tubing. A 



Fig. 32. — Baermann isolation apparatus for soil nematodes. (Orig.) 



fine meshed sieve with one or two layers of muslin cloth in the 

 bottom is set in the funnel and on this the soil sample is placed. 

 The funnel is then filled with water at blood heat to a point 

 above the lower surface of the soil. The majority of the nema- 

 todes under these conditions pass into the water and can be 

 collected. For extensive work a rack of suitable height is used 

 with a battery of funnels held in place by padded crossbars. For 

 many purposes an ordinary ring stand may be used to support 



